Typying text with coroutine

Unity3d-Typer.cs

using UnityEngine;
using UnityEngine.UI;
using System.Collections;

[RequireComponent(typeof(Text))]
public class Typer : MonoBehaviour {

  public string msg = "Replace";
  public float startDelay = 2f;
  public float typeDelay = 0.01f;

  private Text textComp;
  
  void Start () {
    StartCoroutine("TypeIn");
  }
	
  void Awake(){
    textComp = GetComponent<Text>();
  }

  public IEnumerator TypeIn() {
    yield return new WaitForSeconds(startDelay);

    for (int i = 0; i < msg.Length; i++) {
      textComp.text = msg.Substring(0, i+1);
      yield return new WaitForSeconds(typeDelay);
    }
  }

  public IEnumerator TypeOff() {
    for (int i = msg.Length; i >= 0; i--) {
      textComp.text = msg.Substring(0, i);
      yield return new WaitForSeconds(typeDelay);
    }
  }
}